Viscose composition and method of spinning



' staining characteristics.

United States Patent VISCOSE COMPOSITION AND METHOD OF SPINNING MarionR. Lytton, West Chester, Pa.,.assignor to American Viscose Corporation,Philadelphia, Pa, :1 corporation of Delaware No Drawing. ApplicationSeptember 21, 1953; SerialNo. 381,464

17 Claims. (Cl. 18-54) This invention relates to .the production ofshaped bodies of regenerated cellulose from viscose.

In the conventionalmethod of producing shaped bodies of regeneratedcellulose from viscose, a suitable cellulosic material such as purifiedcotton linters, wood pulp, mixtures thereof, and the like is firstconverted to an alkali cellulose by treatment with a causticsodasolution and after shredding the treated cellulose material, it isallowed to age. The aged alkali cellulose is then converted to axanthate by treatment with carbon disulfide. The cellulose xanthate issubsequently dissolved in a caustic soda solution in an amountcalculated to provide a-viscose, of the desired cellulose and alkalicontent. After filtration, the viscose solution is allowed to ripen andis subsequently extruded through 'a shaped-orifice, into a suitablecoagulatingand regenerating bath.

In the-production of filaments, the viscose. is extruded through aspinneret into a coagulating and regenerating bath consisting of anaqueous acid solution containing zinc sulfate. The filament maysubsequently be passed through a hot aqueous bathwhere it is stretchedto improve its properties such as tensile strength. The filament maythen be passed through a dilute aqueous soluti-on of sulfuric acid andsodium sulfate to complete the regeneration of the cellulose, in case itis'not' completely regenerated upon leaving the stretching stage. Thefilament is subsequently subjected to washing, purification, bleaching,possibly other treating operations and drying; being collected eitherbefore or after these treatments.

The filaments as formed by the conventional methods, consist of a skinor outer shell portion and a core portion with a sharp line ofdemarkation between the two. The cross-section of the filaments exhibitsa very irregular or crenulated exterior surface. The skinand-coreportions of the filament represent diiierences in crystalstructure and the different portions possess different swelling-and Thesharply irregular and menulated' surface structure has a relatively lowabrasion resistance and readily picks up foreign particles such as- TheN.N.N'.N'-tetraethanol 1,3-diamino propanol-Z may be added at anydesired stage in the production of the viscose, preferably being addedafter the cellulose xanthate has been dissolved in the caustic solution.the modifier added to and incorporated in the viscose should be atleastabout'Od mole per 100 kgs. of viscose andmay vary over awide-range, namely, from about 0.1 to =ab out 1O and; even upto 20ormoremoles per 100, kgs: oi'viscose. I: prefer to; incorporate in; theviscose. an:

The amount of amount of from.about.0.2.to about 5 moles per 10.0 kgs. ofviscose. Amounts within the preferred range are eifective, however,lesser, or, greater amounts do not adversely af feet the properties, andcharacteristics of theproducts.

Regenerated cellulose filaments prepared fromviscose containing. thesmall amounts of this modifier have, a smooth or non-crenulated surfaceand consist substan: tiaily entirely of skin. Because of the uniformityof crystal structure throughout thefilament, the swelling and stain?ing. characteristics are uniform throughout the crosssection of thefilament. Filaments produced pursuant to this invention andconsistingentirely of, skin have a high toughness and a greater flexing lifewhichmay beat: tributed by. the uniformity in skin structure throughoutthe filament. Although twisting of conventional filaments, as in theproduction of tire cord, results in an appreciable loss of tensilestrength, there is little loss in tensile strength in the production ofconds from the filaments. con: sisting entirely of skin. Filamentsprepared from viscose containing the modifier have a high tensilestrength as compared to, normal regenerated cellulose filaments andhavesuperior abrasion and fatigue resistance character-, istics. Suchfilaments are highly. satisfactory for the production of cords for thereinforcement of rubber products such as pneumatic tire casings, but thefilaments are not restricted to such uses and may be used for othertextile applications.

The invention may be illustrated by reference to the preparation ofregenerated cellulose filaments from a vis: cose containing 7%cellulose, 6% caustic soda, and havinga total carbon disulfide contentof about 41%. The viscose solutions were prepared by xanthating alkalicellulose by the introduction of 36% carbon disulfide and churning forabout 2% hours. The cellulose xanthate was then dissolved in causticsoda solution. An additional 5% carbon disulfide was then added to thechurn and the mass again churned for about one hour. The modifier wasadded to the caustic soda solution and mixed for about /2 hour. Theviscose was then allowed to ripen for about 40 hours at 18 C.

Example 1 Approximately 0.4% (1.5 moles per kgs. of viscose) N.lI.N'.Ntetraethanol 1,3-diamino propanol-Z was addedto and incorporatedin the viscose as described above. The viscose employed in the spinningof filaments had a salt test of 10. The viscose was extruded through aspinneret to form a 250 denier, filament yarn at a rate of-about 10meters per minute. The coagulating and regenerating bath was maintainedat a temperature of about 50 C. and contained 7.5 sulfuric acid, 7.5%zinc sulfate and 20% sodium sulfate. The yarn was passed over a godetfrom which it was conducted througha hot water bath maintained at about90 C. During the travel through the hot water bath, the yarn wasstretched approximately 90%. a bath maintainedat about 55 C. andcontaining 3%' sulfuric acid and 5% sodium sulfate so as to complete theregeneration. box, Washed free of acid and salts and dried.

The individual filaments have a smooth non-crenulated exterior surfaceand consist entirely of skin, no core being detectable at highmagnification. The filamentsof a control yarn spun with the same viscosebut without the addition of the modifier and spun under the same.conditions, exhibit a very irregular and crenulated surface COIC.

The. presence of the modifier: in the,.visc0se permits a reduction inthe zinccontent of the regenerating and The yarn was then passed throughThe yarn was then collected in a spinning coagulating bath withoutadversely affecting the characteristics and properties of the resultingproducts.

Example 2 A viscose solution as described hereinbefore, was prepared and0.2% (0.75 moles per 100 kgs. of viscose) modifier was incorporated inthe viscose. The viscose had a salt test of 9.8 and was spun into a 250denier, 120 filament yarn by extrusion into a bath containing 7.5%sulfuric acid, 8% zinc sulfate and 25% sodium sulfate. The bath wasmaintained at a temperature of 60 C. The extrusion rate was about 10meters per minute. The water bath was maintained at about 90 C. and thefilaments were stretched approximately 20% while passing through the hotwater. The final regenerating bath containing 3% sulfuric acid and 5%sodium sulfate was maintained at about 55 C. The yarn was collected in aspinning box, washed free of acid and salts and dried.

The individual filaments were readily distinguishable from controlfilaments prepared from viscose containing no modifier in that they havea smooth non-crenulated surface and consist entirely of skin.

If desired, small amounts of the modifier may be added to the spinningbath. Since it is water-soluble, some of the modifier will be leachedfrom the filament and will be present in the bath.

The modifier of this invention may be added to any desired viscose suchas those normally used in industry, the specific viscose composition setforth above, being merely for illustrative purposes.

The viscose may contain from about 6% to about 10% cellulose, theparticular source of the cellulose being selected for the ultimate useof the regenerated cellulose product. The caustic soda content may befrom about 4% to about 8% and the carbon disulfide content may be fromabout 30% to about 50% based upon the weight of the cellulose. Themodified viscose, that is, a viscose containing the small amount ofmodifier, may have a salt test above about 5 and preferably above about7 at the time of spinning or extrusion.

The composition of the spinning bath may be varied over a considerablerange and the presence of the modifier of this invention in the viscosepermits the production of yarns of improved properties such as hightenacity, high abrasion resistance and high fatigue resistance withspinning baths having a relatively low zinc content. The spinning bathmay contain from about 5% to about 12% sulfuric acid, from about 15% toabout sodium sulfate and from about 1% to about 10% zinc sulfate. Othermetal sulfates such as iron, manganese, nickei and the like may bepresent and may replace some of the zinc sulfate. The temperature of thespinning bath may be from about C. to about C.

In the production of filaments for such purposes as the fabrication oftire cord, the filaments are preferably stretched after removal from theinitial coagulating and regenerating bath. From the initial spinningbath, the filaments may be passed through a hot aqueous bath which mayconsist of hot water or a dilute acid solution and may be stretched fromabout to about 120%, preferably between and Yarns for other textilepurposes may be stretched about 20% or more. The precise amount ofstretching will be dependent upon the desired tenacity and otherproperties and the specific type of product being produced. It is to beunderstood that the invention is not restricted to the production offilaments and yarns but it is also applicable to other shaped bodiessuch as sheets, films, tubes and the like. The filaments may then bepassed through a final regenerating bath which may contain from about 1%to about 5% sulfuric acid and from about 1% to about 5% sodium sulfatewith or Without small amounts of zinc sulfate if regeneration has notpreviously been completed. The treatment following the finalregenerating bath,

or the stretching operation where regeneration has been completed, mayconsist of a washing step, the application of a finishing orplasticizing material and drying before or after collecting, or mayinclude other steps such as bleaching and the like. The treatment afterregeneration will be dictated by the specific type of shaped body andthe proposed use thereof.

While preferred embodiments of the invention have been disclosed, thedescription is intended to be illus trative and it is to be understoodthat changes and variations may be made without departing from thespirit and scope of the invention as defined by the appended claims.

I claim:

1. As a composition of matter, viscose containing a small amount ofN.N.N'.N'-tetraethanol 1,3-diamino propanol-2.

2. As a composition of matter, viscose containing from about 0.1 mole toabout 20 moles of N.N.N'.N'-tetraethanol 1,3-diamino propanol-2 per 100kgs. of viscose.

3. As a composition of matter, viscose containing from about 0.2 toabout 5 moles of N.N.N.N'-tetraethanol 1,3-diamino propanol-2 per 100kgs. of viscose.

4. As a composition of matter, viscose comprising from about 6% to about10% cellulose, from about 4% to about 8% sodium hydroxide, from about30% to about 50% carbon disulfide based upon the weight of the celluloseand a small amount of N.N.N.N'-tetraethanol 1,3-diamino propanol-2, theamount being based upon the weight of the viscose.

5. As a composition of matter, viscose comprising from about 6% to about10% cellulose, from about 4% to about 8% sodium hydroxide, from about30% to about 50% carbon disulfide based upon the weight of the celluloseand from about 0.1 mole to about 20 moles of N.N.N'.N'-tetraethanol1,3-diamino propanol-2 per 100 kgs. of the viscose.

6. As a composition of matter, viscose comprising from about 6% to about10% cellulose, from about 4% to about 8% sodium hydroxide, from about30% to about 50% carbon disulfide based upon the weight of the celluloseand from about 0.2 to about 5 moles of N.N.N.N'-tetraethanol 1,3-diaminopropanol-2 per 100 kgs. of the viscose.

7. In a method of producing shaped bodies of regenerated cellulose fromviscose, the step which comprises adding to and incorporating in viscosea small amount of N.N.N.N tetraethanol 1,3 diamino propanol-2, theamount being based upon the weight of the viscose.

8. In a method of producing shaped bodies of regenerated cellulose fromviscose, the step which comprises adding to and incorporating in viscosefrom about 0.1 mole to about 20 moles of N.N.N'.N-tetraethanol 1,3-diamino propanol-2 per 100 kgs. of the viscose.

9. In a method of producing shaped bodies of regenerated cellulose fromviscose, the step which comprises adding to and incorporating in viscosefrom about 0.2 to about 5 moles of N.N.N.N-tetraethanol 1,3-diaminopropanol-2 per 100 kgs. of the viscose.

10. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin which comprises spinning viscose containinga small amount of N.N.N.N tetraethanol 1,3 diamino propanol 2, theamount being based upon the weight of the viscose into an aqueous acidicspinning bath containing zinc sulfate.

11. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin which comprises spinning viscose containingfrom about 0.1 mole to about 20 moles of N.N.N'.N-tetraethanol1,3-diamino propanol-2 per 100 kgs. of viscose into an aqueous acidicspinning bath containing from about 1% to about 10% zinc sulfate.

12. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin which comprises spinning viscose containingfrom about 0.2 to about 5 moles of N.N.N'.N'-tetraethanol1,3-diaminopropanoh 2 per 100 kgs. of viscose into an aqueous acidicspinning bath containing from about 1% to about zinc sulfate.

13. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin Which comprises spinning viscose containinga small amount of N.N.N.N' tetraethanol 1,3 diamino propanol 2, theamount being based upon the weight of the viscose, into an aqueousacidic spinning bath containing from about 1% to about 10% zinc sulfateand stretching the body at least 20%.

14. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin which comprises spinning viscose containinga small amount of N.N.N'.N' tetraethanol 1,3 diamino propanol 2, t eamount being based upon the weight of the viscose, into an aqueousacidic spinning bath containing from about 1% to about 10% zinc sulfateand stretching the body between about 80% and about 120%.

15. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin which comprises spinning viscose containingfrom about 0.1 mole to about 20 moles of N.N.N'.N'-tetraethanol1,3-diamino propanol-Z per 100 kgs. of viscose into an aqueous acidicspinning bath containing from about 1% to about 10% 6 zinc sulfate andstretching the body between about and about 120%.

16. The method of producing shaped bodies of regenerated celluloseconsisting entirely of skin which comprises spinning viscose containingfrom about 0.2 to about 5 moles of N.N.N'.N'-tetraethanol 1,3-dian1inopropanol- 2 per kgs. of viscose into an aqueous acidic spinning bathcontaining sulfuric acid and from about 1 to about 10% zinc sulfate,stretching the body between about 80% and about 17. The method ofproducing shaped bodies of regenerated cellulose consisting entirely ofskin which comprises spinning viscose containing a small amount ofN.N.N'.N' tetraethanol 1,3 diamino propanol 2, the amount being basedupon the weight of the viscose, into an aqueous acidic spinning bathcontaining sulfuric acid and from about 1% to about 10% Zinc sulfate,removing the body from the spinning bath before regeneration of thecellulose has been completed, stretching the partially regeneratedcellulose body at least 20% and completing the regeneration of thecellulose.

References Cited in the file of this patent UNITED STATES PATENTS2,535,044 Cox Dec. 26, 1950

10. THE METHOD OF PRODUCING SHAPED BODIES OF REGENERATED CELLULOSECONSISTING ENTIRELY OF SKIN WHICH COMPRISES SPINNING VISCOSE CONTAININGA SMALL AMOUNT OF N.N.N''.N'' - TETRAETHANOL 1,3 - DIAMINO PROPANOL - 2,THE AMOUNT BEING BASED UPON THE WEIGHT OF THE VISCOSE INTO AN AQUEOUSACIDIC SPINNING BATH CONTAINING ZINC SULFATE.